MUS 212

Popular Chord Symbols v. Roman Numerals

The basics ...

POPULAR MUSIC CHORD SYMBOLS

Popular chord symbols are "stand-alone"
symbols, having no intrinsic relationship with the given key.
For example, if a song happens to be in the key of Ab major,
and the chord symbol "C" appears above a note(s), the
resultant chord would be the triad "CEG." The note
"E" is not affected by the four flats in the key
signature.

Likewise, Arabic numbers used in conjunction with
letter-name chords are not affected by the key (as the 9th &
13th are in minor with Roman numeral analysis symbols.)

When the number "7" appears with a popular
chord symbol, e.g, D7, the implied chord structure is a
major-minor seventh chord--root, M3, P5, m7 (D, F#, A,
C)--regardless of the key. The key of the song could be C#
minor, but the D7 symbol still means D, F#, A, C in popular music.

When the number "9" appears with a popular
chord symbol, e.g, F9, the implied chord structure is a
major-minor seventh chord with an added major ninth--root, M3, P5,
m7, M9 (F, A, C, Eb, G). This holds true regardless of
the key. (A "ninth" is equivalent to adding an
octave and a M2 above the root.)

When the number "11" appears with a
popular chord symbol, e.g, A11, the implied chord structure
is a major-minor seventh chord with an added major ninth and perfect
eleventh--root, M3, P5, m7, M9, P11 (A, C#, E, G, B, D). This
holds true regardless of the key. (An "eleventh" is
equivalent to adding an octave and a P4 above the root.)

When the number "13" appears with a
popular chord symbol, e.g, C13, the implied chord structure
is a major-minor seventh chord with an added major ninth, perfect
eleventh and major thirteenth--root, M3, P5, m7, M9, P11, M13 (C, E,
G, Bb, D, F, A). This holds true regardless of the
key. (A "thirteenth" is equivalent to adding an
octave and a M6 above the root.)

When something other than a "major-minor
seventh-based" chord is desired, the basic structure must be
indicated.

For diminished structures extending more than a
seventh, it is preferable to indicate only the structure of the
diminished seventh chord, in terms of half- or fully-diminished,
then, use the designation "add 9," "add 11,"
"add 13," etc. For example, the symbol Cdim9 means a
fully diminished seventh chord with an added major
ninth. It is less confusing, however, to write Cdim7(add9)
(= C, Eb, Gb, Bbb, D) to eliminate possible
confusion. Half-diminished chords are preferably notated as mi7b5.
E.g., Cmi7(b5) = C, Eb, Gb, Bb.
The half-diminished ninth chord would be written as Cmi9(b5)
= C, Eb, Gb, Bb, D.

The trend has been to move away from graphic symbols
in popular chord symbol notation, thereby eliminating the use of the
"circle" for full-diminished and "circle/slash"
for half-diminished. E.g., Cdim, rather than Co.
Graphic symbols can be confusing at times. E.g., the former
graphic symbol for a major-major seventh chord was a small
triangle. Writing CMA7 removes any doubt as to the type of
chord desired. The "+" symbol for augmented
(applying only to the fifth of the chord) has also largely
been abandoned in favor of "#5," as well. E.g., C7#5
= C, E, G#, Bb, or Caug, rather than C+ (C, E, G#).

In popular chord symbol notation, altered tones are
indicated on an individual basis. These are usually self
explanatory. E.g., D7(b9) = D, F#, A, C, Eb.
D9(#11) = D, F#, A, C, E, G#. At times, chord symbols can
become quite complex with up to three or four altered tones (a
pianist's veritable nightmare).

Inversions are indicated by giving the chord,
followed by a slash ("/") and the bass note. E.g., a
first inversion C triad would be written C/E, indicating a C chord
with an E in the bass. A second inversion G triad would be
written G/D, indicating a G chord with a D in the bass. Db9/Ab
means that an Ab is the bass note of a Db9 chord.

ROMAN NUMERAL ANALYSIS SYMBOLS

Roman numeral analysis symbols are indeed tied to
their key. Major chord structures are represented by uppercase
numerals, and minor structures are represented by lowercase
numerals.

Using Roman numeral analysis symbols, in the key of
C major, the symbol I7 refers to a tonic major triad with an added diatonic
major seventh--in this case, a B natural (C, E, G, B). The
popular chord symbol C7, however, represents a major-minor seventh
chord, including the added minor seventh, Bb (C, E, G, Bb).
To reproduce the I7 chord using pop symbols, the indication would be
CMA7.

Using Roman numeral analysis symbols, in the key of
C major, the symbol ii7 refers to a supertonic minor triad with an
added diatonic minor seventh--in this case a C natural (D, F,
A, C). The popular chord symbol D7, however, represents a
major-minor seventh chord (D, F#, A, C). To reproduce the ii7
chord using pop symbols, the indication would be Dmi7.

In major keys, the 9, 11 or 13 added to Roman
numeral symbols will be diatonic to the given major
key. To produce an altered 9, 11 or 13 in major, a sharp or
flat must appear before the number. E.g., in Bb major,
V9 = F, A, C, Eb, G. The Eb is diatonic to the
key of Bb major. Vb9 = F, A, C, Eb, Gb.
Again, Eb is diatonic, but Gb is not. A flat is
necessary in major to lower the 9th by a half step.

In minor keys, the 9, 11 or 13 added to Roman
numeral symbols will also be diatonic to the given minor
key. In minor, the 9th and 13th of the dominant
(V) chord are also affected. (The 11th is not affected by the
key signature due to its being equivalent to the 4th scale
degree.)

In the key of C minor, the V9 chord = G, B,
D, F, Ab. (B is natural due to being the raised leading
tone, which creates the normal major dominant triad.) The 9th
(Ab) is lowered, however, due to the key signature (three
flats). It is not necessary to indicate the lowered ninth in
minor using the Roman numeral system because the (flat) ninth is
simply a diatonic note. To reproduce this chord using pop
symbols, the flat ninth must be indicated: G7b9.
In the key of C major, the V9 chord = G, B, D, F, A.
("A" is natural because there are no sharps or flats in
the key signature.)

In the key of C minor, the V13 chord = G, B,
D, F, Ab, C, Eb. The 13th is lowered because of
the Eb in the key signature. (Again, B is natural due
to its leading-tone function.) It is not necessary to indicate
the lowered 13th in minor using the Roman numeral system because the
(flat) thirteen is simply a diatonic note. To reproduce this
chord using pop symbols, the flat 13th and flat 9th must be
indicated: G11(b13, b9). (Ideally, these
two numbers should appear vertically with the larger number on top
... a bit difficult to do with a word processor. In the key of
C major, the V13 chord = G, B, D, F, A, C, E. (Both A
and E are natural because there are no sharps or flats in the key
signature.)

Bottom line: The 9th and 13th are diatonic to
the key (major or minor) unless an indication is given (via flat or
sharp) that these pitches are to be altered. These alterations
would normally appear in major keys since the notes are already
lowered in minor keys. (FYI, in jazz styles, the #9 is also a
common alteration, e.g., C7#9 = C, E, G, Bb, D#.)

These extended-chord sonorities may also be used in
secondary functions. The important point to keep in mind is
that the secondary embellishing chords, such as V7/? and V9/? must
have a major third, regardless of the key signature.
The V7/? chord will be a typical major-minor 7th chord (R, M3, P5,
m7). The V9/? chord will be a typical major-minor 7th chord,
but the 9th will be affected by the key signature.
E.g., in Bb major, V9/vi = D, F#, A, C, Eb (Eb,
lowered 9th, due to the key signature). Again in Bb
major, V9/V = C, E, G, Bb, D (D natural, major 9th, due to
the key signature.)

The text does not address secondary chords of the
11th and 13th, as they are not common. Their structure,
however, would be the typical major-minor seventh chord as the
basis, and all extended notes (9, 11, 13) would be determined by the
key signature.